JBR-6704: Fix extra IME events when a ctrl shortcut causes window focus switch [macOS]

src/java.desktop/macosx/native/libawt_lwawt/awt/AWTView.m

@@ -45,6 +45,9 @@
 // keyboard layout
 static NSString *kbdLayout;
 
+// workaround for JBR-6704
+static unichar lastCtrlCombo;
+
 @interface AWTView()
 @property (retain) CDropTarget *_dropTarget;
 @property (retain) CDragSource *_dragSource;
@@ -87,6 +90,7 @@ extern bool isSystemShortcut_NextWindowInApplication(NSUInteger modifiersMask, i
     fInputMethodLOCKABLE = NULL;
     fKeyEventsNeeded = NO;
     fProcessingKeystroke = NO;
+    lastCtrlCombo = 0;
 
     fEnablePressAndHold = shouldUsePressAndHold();
     fInPressAndHold = NO;
@@ -365,6 +369,12 @@ static void debugPrintNSEvent(NSEvent* event, const char* comment) {
 
     NSString *eventCharacters = [event characters];
 
+    if (([event modifierFlags] & NSControlKeyMask) && [eventCharacters length] == 1) {
+        lastCtrlCombo = [eventCharacters characterAtIndex:0];
+    } else {
+        lastCtrlCombo = 0;
+    }
+
     // Allow TSM to look at the event and potentially send back NSTextInputClient messages.
     [self interpretKeyEvents:[NSArray arrayWithObject:event]];
 
@@ -1140,6 +1150,14 @@ static jclass jc_CInputMethod = NULL;
     fprintf(stderr, "AWTView InputMethod Selector Called : [insertText]: %s\n", [aString UTF8String]);
 #endif // IM_DEBUG
 
+    NSMutableString * useString = [self parseString:aString];
+
+    // See JBR-6704
+    if (lastCtrlCombo && !fProcessingKeystroke && [useString length] == 1 && [useString characterAtIndex:0] == lastCtrlCombo) {
+        lastCtrlCombo = 0;
+        return;
+    }
+
     if (fInputMethodLOCKABLE == NULL) {
         return;
     }
@@ -1152,8 +1170,6 @@ static jclass jc_CInputMethod = NULL;
     // text, or 'text in progress'.  We also need to send the event if we get an insert text out of the blue!
     // (i.e., when the user uses the Character palette or Inkwell), or when the string to insert is a complex
     // Unicode value.
-
-    NSMutableString * useString = [self parseString:aString];
     BOOL usingComplexIM = [self hasMarkedText] || !fProcessingKeystroke;
 
 #ifdef IM_DEBUG
@@ -1163,6 +1179,7 @@ static jclass jc_CInputMethod = NULL;
     NSLog(@"insertText kbdlayout %@ ",(NSString *)kbdLayout);
 
     NSLog(@"utf8Length %lu utf16Length %lu", (unsigned long)utf8Length, (unsigned long)utf16Length);
+    NSLog(@"hasMarkedText: %s, fProcessingKeyStroke: %s", [self hasMarkedText] ? "YES" : "NO", fProcessingKeystroke ? "YES" : "NO");
 #endif // IM_DEBUG
 
     JNIEnv *env = [ThreadUtilities getJNIEnv];
@@ -1178,7 +1195,7 @@ static jclass jc_CInputMethod = NULL;
 
     if (usingComplexIM) {
         DECLARE_METHOD(jm_insertText, jc_CInputMethod, "insertText", "(Ljava/lang/String;)V");
-        jstring insertedText =  NSStringToJavaString(env, useString);
+        jstring insertedText = NSStringToJavaString(env, useString);
         (*env)->CallVoidMethod(env, fInputMethodLOCKABLE, jm_insertText, insertedText);
         CHECK_EXCEPTION();
         (*env)->DeleteLocalRef(env, insertedText);

test/jdk/jb/sun/awt/macos/InputMethodTest/CtrlShortcutNewWindowTest.java

@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2000-2024 JetBrains s.r.o.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * @test
+ * @summary Regression test for JBR-6704 Extra IME event fired when pressing a keystroke containing Ctrl and focus moving to a different window
+ * @modules java.desktop/sun.lwawt.macosx
+ * @run main InputMethodTest CtrlShortcutNewWindowTest
+ * @requires (jdk.version.major >= 8 & os.family == "mac")
+ */
+
+import javax.swing.*;
+
+import java.awt.event.FocusEvent;
+import java.awt.event.FocusListener;
+import java.awt.event.KeyAdapter;
+import java.awt.event.KeyEvent;
+
+import static java.awt.event.KeyEvent.*;
+
+public class CtrlShortcutNewWindowTest implements Runnable {
+    @Override
+    public void run() {
+        var frame = new JFrame();
+        frame.setSize(300, 300);
+        frame.setLocation(100, 100);
+        JTextField textField = new JTextField();
+        frame.add(textField);
+        textField.requestFocusInWindow();
+
+        final boolean[] keyPressed = {false};
+
+        InputMethodTest.textArea.addKeyListener(new KeyAdapter() {
+            @Override
+            public void keyPressed(KeyEvent e) {
+                if (e.getKeyCode() == VK_BACK_QUOTE && (e.getModifiersEx() & KeyEvent.CTRL_DOWN_MASK) != 0) {
+                    keyPressed[0] = true;
+                    frame.setVisible(true);
+                }
+            }
+        });
+
+        InputMethodTest.section("Ctrl+Backtick");
+        InputMethodTest.layout("com.apple.keylayout.ABC");
+        InputMethodTest.type(VK_BACK_QUOTE, CTRL_DOWN_MASK);
+        InputMethodTest.delay(500);
+
+        if (!keyPressed[0]) {
+            InputMethodTest.fail("Ctrl+Backtick key combination not detected");
+        }
+
+        if (!textField.getText().isEmpty()) {
+            InputMethodTest.fail("Extra characters in the text field");
+        }
+
+        frame.setVisible(false);
+        frame.dispose();
+    }
+}

test/jdk/jb/sun/awt/macos/InputMethodTest/InputMethodTest.java

@@ -46,6 +46,7 @@ public class InputMethodTest {
     private static final List<KeyEvent> triggeredEvents = new ArrayList<>();
 
     private enum TestCases {
+        CtrlShortcutNewWindowTest (new CtrlShortcutNewWindowTest()),
         DeadKeysTest (new DeadKeysTest()),
         FocusMoveUncommitedCharactersTest (new FocusMoveUncommitedCharactersTest()),
         KeyCodesTest (new KeyCodesTest()),
@@ -332,4 +333,8 @@ public class InputMethodTest {
     public static void fail(String comment) {
         expectTrue(false, comment);
     }
+
+    public static void delay(int millis) {
+        robot.delay(millis);
+    }
 }